Light source device and projector

ABSTRACT

A light source device according to an aspect of the present disclosure includes a light source unit, a wavelength conversion unit including a wavelength conversion wheel, and a wheel housing configured to expose a part of the wavelength conversion wheel and house the wavelength conversion wheel, and an optical unit including a condensing optical system, a pickup optical system, and an optical housing. The light source unit and the optical unit are fixed in a sealed state. In the optical unit and the wavelength conversion unit, a part of the wavelength conversion wheel exposed via a first opening section of the wheel housing is disposed on an optical path between the condensing optical system and the pickup optical system. The second opening section of the optical housing and the first opening section of the wheel housing are fixed in a sealed state.

The present application is based on, and claims priority from JPApplication Serial Number 2021-184053, filed Nov. 11, 2021, thedisclosure of which is hereby incorporated by reference herein in itsentirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a light source device and a projector.

2. Related Art

A projector described in JP-A-2016-51073 (Patent Literature 1) cools asemiconductor laser and a fluorescent screen wheel, which are componentsof a light source device, with a cooling device.

However, in the projector, dust intruding into the inside of theprojector adheres to a lens and the fluorescent screen wheel of thelight source device and causes deterioration and heat generation ofcomponents.

SUMMARY

According to a first aspect of the present disclosure, there is provideda light source device including: a light source unit including a lightemitting element; a wavelength conversion unit including: a wavelengthconversion wheel configured to make excitation light emitted from thelight emitting element incident from a first surface and emitwavelength-converted light obtained by wavelength-converting theexcitation light from a second surface opposite to the first surface;and a wheel housing including a first opening section for exposing apart of the wavelength conversion wheel and configured to house thewavelength conversion wheel; and an optical unit including: a condensingoptical system including a first lens for condensing the excitationlight on the wavelength conversion wheel; a pickup optical systemconfigured to pick up the wavelength-converted light; and an opticalhousing including a second opening section for receiving a part of thewavelength conversion wheel and configured to hold the condensingoptical system and the pickup optical system to locate a part of thewavelength conversion wheel on an optical path between the condensingoptical system and the pickup optical system. The light source unit andthe optical unit are fixed in a sealed state. In the optical unit andthe wavelength conversion unit, a part of the wavelength conversionwheel exposed via the first opening section of the wheel housing isdisposed on the optical path between the condensing optical system andthe pickup optical system via the second opening section of the opticalhousing. The second opening section of the optical housing and the firstopening section of the wheel housing are fixed in a sealed state.

According to a second aspect of the present disclosure, there isprovided a projector including: the light source device according to thefirst aspect; an image forming device configured to form light outputfrom the light source device into image light; and a projection opticaldevice configured to project the image light output from the imageforming device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing an overall configuration of a projector in afirst embodiment.

FIG. 2 is an exploded perspective view showing an attachment state of alight source device.

FIG. 3 is an exploded perspective view showing the configuration of thelight source device.

FIG. 4 is a sectional view showing the configuration of the light sourcedevice.

FIG. 5 is a perspective view showing the configuration of a wavelengthconversion unit.

FIG. 6A is a diagram showing the configuration on a light incidentsurface side of a wavelength conversion wheel.

FIG. 6B is a diagram showing the configuration on a light emissionsurface side of the wavelength conversion wheel.

FIG. 7 is a perspective view showing the configuration of an opticalhousing.

FIG. 8A is a side view of the optical housing viewed from a −X side.

FIG. 8B is a side view of the optical housing viewed from a +X side.

FIG. 9 is a sectional view by a XI-XI line arrow view of FIG. 4 .

FIG. 10 is a perspective view showing the configuration of a crosssection by a surface including a X-X line in FIG. 4 .

FIG. 11 is a perspective view showing a schematic configuration of alight source device in a second embodiment.

FIG. 12 is a plan view showing the configuration of a light sourcedevice in a modification of the second embodiment.

FIG. 13 is a perspective view showing a schematic configuration of alight source device in a third embodiment.

FIG. 14 is an exploded perspective view showing the configuration of thelight source device in the third embodiment.

FIG. 15A is a bottom view of an optical housing in the third embodimentviewed from a −Z side.

FIG. 15B is a bottom view of the optical housing in the third embodimentviewed from a +Z side.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the present disclosure are explained in detail below withreference to the drawings.

In the drawings referred to in the following explanation, characteristicportions are sometimes enlarged and shown for convenience in order toclearly show characteristics. Dimension ratios and the like ofcomponents are not always the same as actual dimension ratios and thelike.

First Embodiment

FIG. 1 is a diagram showing an overall configuration of a projector in afirst embodiment.

A projector 1 in this embodiment modulates illumination light emittedfrom a light source device 2 to generate image light corresponding toimage information and enlarges and projects the formed image light ontoa projection surface such as a screen.

As shown in FIG. 1 , the projector 1 includes a light source device 2,an image forming device 3, a projection optical device 6, and anexterior housing 7.

The light source device 2 supplies white illumination light WL to theimage forming device 3. The light source device 2 in this embodimentgenerates the illumination light WL including fluorescent lightgenerated by wavelength-converting, with a phosphor, excitation lightemitted from a light source module including a semiconductor laser. Theconfiguration of the light source device 2 is explained below.

The image forming device 3 includes light modulation panels 10R, 10G,and 10B and a cross dichroic prism 11. Each of the light modulationpanels 10R, 10G, and 10B modulates color light made incident thereonaccording to image information to form image light. Each of the lightmodulation panels 10R, 10G, and 10B is configured by a lighttransmissive liquid crystal panel.

The cross dichroic prism 11 combines image lights emitted from the lightmodulation panels 10R, 10G, and 10B. The cross dichroic prism 11 isformed in a substantially square shape in a plane view obtained bypasting together four right-angle prisms. A dielectric multilayer filmis provided on a substantially X-shaped interface where the right-angleprisms are pasted together.

Based on such a configuration, the image forming device 3 in thisembodiment combines the image lights of the colors to generatefull-color image light.

In this embodiment, field lenses 12R, 12G, and 12B are provided on lightincident sides of the respective light modulation panels 10R, 10G, and10B.

Although not illustrated, incident side polarization plates are disposedbetween the light modulation panels 10R, 10G, and 10B and the fieldlenses 12R, 12G, and 12B and emission side polarization plates aredisposed between the light modulation panels 10R, 10G, and 10B and thecross dichroic prism 11.

In this embodiment, the image forming device 3 further includes a colorseparation optical system 4 and a uniform illumination optical system 5.

The illumination light WL emitted from the light source device 2 is madeincident on the uniform illumination optical system 5.

The uniform illumination optical system 5 includes a first lens array 5a, a second lens array 5 b, a polarization conversion element 5 c, and asuperimposition lens 5 d.

The first lens array 5 a includes a plurality of first small lenses fordividing the illumination light WL made incident from the light sourcedevice 2 into a plurality of partial light beams. The plurality of firstsmall lenses are arrayed in a matrix shape in a plane orthogonal to anoptical axis AX1 of the illumination light WL.

The second lens array 5 b includes a plurality of second small lensescorresponding to the plurality of first small lenses of the first lensarray 5 a. The plurality of second small lenses are arrayed in a matrixshape in a plane orthogonal to the optical axis AX1.

The second lens array 5 b forms, in conjunction with the superimpositionlens 5 d, images of the first small lenses of the first lens array 5 arespectively in the vicinities of image forming regions of the lightmodulation panels 10R, 10G, and 10B.

The polarization conversion element 5 c converts light emitted from thesecond lens array 5 b into linearly polarized light in one direction.The polarization conversion element 5 c includes, for example, apolarization separation film and a phase difference plate not shown inFIG. 1 .

The superimposition lens 5 d condenses the partial light beams emittedfrom the polarization conversion element 5 c and superimposes thepartial light beams respectively in the vicinities of the image formingregions of the light modulation panels 10R, 10G, and 10B.

The color separation optical system 4 separates the illumination lightWL passed through the uniform illumination optical system 5 into redlight LR, green light LG, and blue light LB and guides the red light LR,the green light LG, and the blue light LB to the light modulation panels10R, 10G, and 10B. The color separation optical system 4 includes afirst dichroic mirror 41, a second dichroic mirror 42, a firstreflection mirror 43, a second reflection mirror 44, a third reflectionmirror 45, a first relay lens 46, and a second relay lens 47.

The first dichroic mirror 41 reflects the red light LR and transmits thegreen light LG and the blue light LB. Of the green light LG and the bluelight LB transmitted through the first dichroic mirror 41, the seconddichroic mirror 42 reflects the green light LG and transmits the bluelight LB. The first reflection mirror 43 reflects the red light LR. Thesecond reflection mirror 44 and the third reflection mirror 45 reflectthe blue light LB. The first relay lens 46 is disposed between thesecond dichroic mirror 42 and the second reflection mirror 44. Thesecond relay lens 47 is disposed between the second reflection mirror 44and the third reflection mirror 45.

The projection optical device 6 includes a projection lens group. Imagelight combined by the cross dichroic prism 11 of the image formingdevice 3 is made incident on the projection optical device 6. Althoughnot illustrated, a lens shift mechanism for shifting an optical axis AX2of the projection optical device 6 may be provided in a connectingportion of the projection optical device 6 and the cross dichroic prism11 of the image forming device 3.

Based on such a configuration, the projector 1 in this embodiment canenlarge and project the image light generated by the image formingdevice 3 toward a projection surface such as a screen. Consequently, anenlarged color video is displayed on the screen.

The exterior housing 7 houses the light source device 2 and the imageforming device 3 on the inside and configures the exterior of theprojector 1.

Light Source Device

Subsequently, the configuration of the light source device 2 isexplained.

FIG. 2 is an exploded perspective view showing an attachment state ofthe light source device 2 to the exterior housing 7. In FIG. 2 , abottom plate section 17, which is a part of the exterior housing 7, isshown in order to show the internal structure of the projector 1.

In the following explanation concerning the light source device, an XYZorthogonal coordinate system is used according to necessity.

In the drawings, a Y axis is an axis along the optical axis AX1 of theillumination light WL emitted from the light source device 2 toward theimage forming device 3 shown in FIG. 1 . A Z axis is an axis orthogonalto the Y axis and orthogonal to a plate surface of the bottom platesection 17 of the exterior housing 7. An X axis is an axis orthogonal tothe Y axis and the Z axis.

In the following explanation in this embodiment, for example, adirection along the Z axis is referred to as “up-down direction Z” inthe light source device 2, +Z is referred to as “upper side”, −Z isreferred to as “lower side”, a direction along the X axis is referred toas “left-right direction X” in the light source device 2, +X that is arear side opposite to the front of the projector 1 in which theprojection optical device 6 is provided is referred to as “right side”,−X that is the front side of the projector 1 is referred to as “leftside”, a direction along the Y axis is referred to as “front-reardirection Y” in the light source device 2, +Y is referred to as “frontside”, and −Y is referred to as “rear side”.

The up-down direction Z, the left-right direction X, and the front-reardirection Y are simply names for explaining a disposition relation amongconstituent members of the light source device 2 and do not defineactual setting postures and directions in the light source device 2 andthe projector 1.

As shown in FIG. 2 , the light source device 2 in this embodiment isheld on the bottom plate section 17 of the exterior housing 7 via screwmembers 9. The bottom plate section 17 includes alight source holdingmember 18 for holding the light source device 2. The light sourceholding member 18 includes a plurality of screw fastening sections 18 aprojecting from the bottom plate section 17 to the upper side +Z and aplurality of positioning sections 18 b projecting from the bottom platesection 17 to the upper side +Z . The plurality of screw fasteningsections 18 a are parts where the screw members 9 are fastened. Theplurality of positioning sections 18 b are pins for positioning thelight source device 2 in a predetermined position with respect to thebottom plate section 17. At least two positioning sections 18 b areprovided. The numbers and disposition of the screw fastening sections 18a and the positioning sections 18 b are not limited to the form shown inFIG. 2 and can be changed as appropriate according to the configurationof the light source device 2.

The light source device 2 in this embodiment includes a light sourceunit 20, a wavelength conversion unit 30, a cooling unit 50, and anoptical unit 40. The cooling unit 50 includes a first cooling section50A that cools the light source unit 20 and a second cooling section 50Bthat cools the optical unit 40.

The first cooling section 50A includes a first heat radiating section 51a and a first heat conducting section 52 a. The second cooling section50B includes a second heat radiating section 51 b and a second heatconducting section 52 b. In this embodiment, the first heat radiatingsection 51 a and the second heat radiating section 51 b are collectivelyreferred to as heat radiating section 51 and the first heat conductingsection 52 a and the second heat conducting section 52 b arecollectively referred to as heat conducting section 52. That is, thecooling unit 50 includes the heat radiating section 51 disposed inparallel to the optical unit 40 and the heat conducting section 52 thatconducts heat received by a base member 23 of the light source unit 20to the heat radiating section 51.

In this embodiment, the heat radiating section 51 is disposed inparallel to the left side −X of the light source unit 20 when viewedfrom a position on the +Y side.

The first heat conducting section 52 a thermally connects the first heatradiating section 51 a and the base member 23 of the light source unit20. The thermally connecting means a state in which two members areconnected to be capable of transferring heat. Another member may beinterposed between the two members if the heat transfer is possiblebetween the two members.

The heat received by the base member 23 is conducted to the first heatradiating section 51 a via the first heat conducting section 52 a. Thefirst heat radiating section 51 a is configured by a heat sink includinga plurality of heat radiation fins and emits heat conducted from thefirst heat conducting section 52 a. As the first heat conducting section52 a, for example, other than graphite, copper, and the like, a heatpipe, a vapor chamber, and the like that make use of evaporation andcondensation of a coolant can also be used. In the case of thisembodiment, the first heat conducting section 52 a is configured by aheat pipe.

The second heat radiating section 51 b is disposed in parallel to theleft side −X of the light source unit 20 and the upper side +Z of thefirst heat radiating section 51 a when viewed from a position on the +Yside.

The second heat conducting section 52 b thermally connects the secondheat radiating section 51 b and a lid body 53 provided in the opticalunit 40. The lid body 53 is configured by a sheet metal member made ofmetal excellent in thermal conductivity.

Heat received by the lid body 53 is conducted to the second heatradiating section 51 b via the second heat conducting section 52 b. Thesecond heat radiating section 51 b is configured by a heat sinkincluding a plurality of heat radiation fins and emits heat conductedfrom the second heat conducting section 52 b. As the second heatconducting section 52 b, for example, other than graphite, copper, andthe like, a heat pipe, a vapor chamber, and the like that make use ofevaporation and condensation of a coolant can also be used. In the caseof this embodiment, the second heat conducting section 52 b isconfigured by a heat pipe.

FIG. 3 is an exploded perspective view showing the configuration of thelight source device 2. FIG. 4 is a sectional view showing theconfiguration of the light source device 2. FIG. 4 is a sectional viewin the left-right direction X on an optical axis AX3 of a condensingoptical system 60 explained below.

As shown in FIGS. 3 and 4 , the light source device 2 in this embodimentincludes the light source unit 20, the optical unit 40, and thewavelength conversion unit 30. In FIGS. 3 and 4 , the cooling unit 50 isnot shown in order to clearly show the figures.

Light Source Unit

First, the configuration of the light source unit 20 is explained.

As shown in FIGS. 3 and 4 , the light source unit 20 includes aplurality of light emitting elements 21, a plurality of mountingsubstrates 22, and the base member 23. The plurality of light emittingelements 21 include first light emitting elements 211 and second lightemitting elements 212. The plurality of mounting substrates 22 includefirst mounting substrates 221 on which the first light emitting elements211 are mounted and second mounting substrates 222 on which the secondlight emitting elements 212 are mounted.

The base member 23 is fixed to the optical unit 40 by screw members 24.The base member 23 includes a fixed section 23 a fixed to the lightsource unit 20 and a recess 23 b formed to recess to the rear side −Yfrom the surface of the fixed section 23 a. In the case of thisembodiment, the fixed section 23 a is disposed to be separated into twoin the left-right direction X by the recess 23 b.

In the base member 23, the first mounting substrates 221 and the secondmounting substrates 222 are placed in the recess 23 b. The base member23 in this embodiment includes the recess 23 b to secure a space formounting the first mounting substrates 221 and the second mountingsubstrates 222 between the base member 23 and the optical unit 40.

In the case of this embodiment, as shown in FIG. 3 , two first mountingsubstrates 221 and two second mounting substrates 222 are placed on thebase member 23. The two first mounting substrates 221 are placed on thebase member 23 side by side in the up-down direction Z. The two secondmounting substrates 222 are placed on the base member 23 side by side inthe up-down direction Z. The first mounting substrates 221 and thesecond mounting substrates 222 are placed on the base member 23 to beadjacent to each other in the left-right direction X.

On each of the first mounting substrates 221, two first light emittingelements 211 are mounted side by side in the left-right direction X. Thenumber of the first light emitting elements 211 mounted on the firstmounting substrate 221 is not limited to this.

As shown in FIG. 4 , the first light emitting element 211 includes, forexample, a plurality of laser elements and a collimator lens. The firstlight emitting element 211 emits excitation light B1 formed by bluelight having a peak wavelength within a range of, for example, 380 nm to495 nm.

On each of the second mounting substrates 222, one second light emittingelement 212 is mounted. The number of the second light emitting elements212 mounted on the second mounting substrate 222 is not limited to this.

The second light emitting element 212 has the same configuration as theconfiguration of the first light emitting element 211. The second lightemitting element 212 includes, for example, a plurality of laserelements and a collimator lens. Like the first light emitting element211, the second light emitting element 212 emits excitation light B2formed by blue light having a peak wavelength within a range of, forexample, 380 nm to 495 nm.

Based on such a configuration, the light source unit 20 emits excitationlight B including a plurality of excitation lights B1 and B2 toward theoptical unit 40.

As shown in FIG. 3 , the recess 23 b pierces through the base member 23in the up-down direction Z. In the light source unit 20 in thisembodiment, the end portions in the upper side +Z and the lower side −Zof the recess 23 b are respectively closed by a pair of plate materials26. The plate materials 26 are fixed to, for example, the upper end faceand the lower end face of a light-source fixing section 70 via the screwmembers 24.

In this embodiment, a sheet-like sealing member 27 is provided betweenthe plate materials 26 and the base member 23. In the case of thisembodiment, as shown in FIG. 4 , a plate-like sealing member 27 isdisposed between the base member 23 of the light source unit 20 and aholding surface 71 of the light-source fixing section 70. That is, anoptical housing 62 of the light source unit 20 and the base member 23 ofthe optical unit 40 are fixed in a sealed state. Accordingly, dust isprevented from intruding into the recess 23 b of the base member 23 froma gap between the optical housing 62 and the base member 23.Accordingly, a deficiency such as heat generation or the like due toadhesion of dust to the first light emitting elements 211 and the secondlight emitting elements 212 mounted in the recess 23 b is prevented fromoccurring.

Optical Unit

Subsequently, the configuration of the optical unit 40 is explained.

As shown in FIG. 4 , the optical unit 40 includes a condensing opticalsystem 60, a pickup optical system 61, an optical housing 62 that holdsthe condensing optical system 60 and the pickup optical system 61, adiffusion plate 65, and a lid body 53.

The condensing optical system 60 includes a plurality of lenses. Thecondensing optical system 60 in this embodiment is configured by twoconvex lenses including a first lens 60 a and a second lens 60 b. Thenumber of lenses configuring the condensing optical system 60 is notparticularly limited.

The first lens 60 a is disposed to be opposed to the light source unit20. That is, the first lens 60 a is a lens located closest to the lightincident side in the condensing optical system 60.

The second lens 60 b is disposed on the opposite side of the lightsource unit 20 in the first lens 60 a, that is, a light emission side ofthe first lens 60 a.

In the condensing optical system 60 in this embodiment, the diameter ofthe second lens 60 b located on a wavelength conversion wheel 31 side issmaller than the diameter of the first lens 60 a located closer to thelight incident side than the second lens 60 b. That is, the lenses 60 aand 60 b configuring the condensing optical system 60 have a largerouter diameter in a radial direction orthogonal to the optical axis AX3of the condensing optical system 60 as the lenses 60 a and 60 b arefurther away from the wavelength conversion unit 30. The optical axisAX3 coincides with the optical axis of the first lens 60 a and thesecond lens 60 b configuring the condensing optical system 60. As shownin FIG. 3 , the optical axis AX3 of the condensing optical system 60coincides with the optical axis AX1 of the illumination light WL emittedfrom the light source device 2.

The condensing optical system 60 in this embodiment further includes aprism member 63, which is an optical-path changing member. The prismmember 63 is disposed in a position opposed to the second light emittingelement 212 and not opposed to the first light emitting element 211 withrespect to the light source unit 20.

In the case of this embodiment, the wavelength conversion unit 30 isdisposed on the left side −X, which is one side in the left-rightdirection X, with respect to the optical housing 62 when viewed from aposition on the +Y side in the left-right direction X, which is a firstdirection, crossing the optical axis AX3 of the condensing opticalsystem 60 including the first lens 60 a. The prism member 63 is disposedon the right side +X, which is the other side in the left-rightdirection X, in the optical housing 62.

That is, in the case of this embodiment, the wavelength conversion unit30 is disposed, with respect to the optical housing 62, on the left side−X opposite to the right side +X where the prism member 63 is providedin the optical housing 62.

In this embodiment, the excitation light B1 emitted from the first lightemitting element 211 is directly made incident on the first lens 60 a ofthe condensing optical system 60 as shown in FIG. 4 . That is, theexcitation light B1 is made incident on the first lens 60 a of thecondensing optical system 60 without being made incident on the prismmember 63. On the other hand, the excitation light B2 emitted from thesecond light emitting element 212 is made incident on the first lens 60a through the prism member 63.

The prism member 63 is a member that changes an optical path of theexcitation light B2 emitted from the second light emitting element 212.

The prism member 63 in this embodiment is configured by a prism member,a plane shape of which is a parallelogram.

The prism member 63 includes a first reflection surface 63 a and asecond reflection surface 63 b separated in the left-right direction Xin which the first light emitting element 211 and the second lightemitting element 212 are arranged. The first reflection surface 63 a isdisposed on the optical axis of the excitation light B2 emitted from thesecond light emitting element 212. The first reflection surface 63 areflects the excitation light B2 emitted from the second light emittingelement 212 to the left side −X. That is, the first reflection surface63 a reflects the excitation light B2 emitted from the second lightemitting element 212 in a direction in which the excitation light B2 isbrought closer to the excitation light B1 emitted from the first lightemitting element 211. The excitation light B2 reflected on the firstreflection surface 63 a is made incident on the second reflectionsurface 63 b.

The second reflection surface 63 b reflects, along the optical axis ofthe first light emitting element 211, the excitation light B2 reflectedfrom the first reflection surface 63 a and makes the excitation light B2incident on the first lens 60 a.

The optical path of the excitation light B2 passed through the prismmember 63 in this way is shifted to the left side −X compared withbefore the excitation light B2 passes through the prism member 63.Accordingly, the prism member 63 is capable of reducing a light beamwidth in the left-right direction X in the excitation light B includingthe plurality of excitation lights B1 and B2.

The second reflection surface 63 b of the prism member 63 is locatedbetween the first lens 60 a and the first mounting substrate 221 in thefront-rear direction Y extending along the optical axis AX3 of the firstlens 60 a of the condensing optical system 60. That is, the secondreflection surface 63 b of the prism member 63 is disposed to overlapthe first mounting substrate 221 when being viewed in a plane view alongthe front-rear direction Y. Consequently, the second reflection surface63 b of the prism member 63 is disposed in a position closer to theoptical axis of the first lens 60 a. Since the second reflection surface63 b does not planarly overlap the first light emitting element 211, thesecond reflection surface 63 b does not block the excitation light B1made incident on the first lens 60 a.

A case is examined in which the second reflection surface 63 b isdisposed in a position overlapping the second mounting substrate 222 inthe front-rear direction Y or a position overlapping a gap between thefirst mounting substrate 221 and the second mounting substrate 222.

In this case, since the second reflection surface 63 b of the prismmember 63 is disposed in a position further apart from the optical axisof the first lens 60 a, a light beam width of the excitation light Bcannot be sufficiently reduced. Accordingly, it is necessary to increasethe lens diameter of the first lens 60 a because the light beam width ofthe excitation light B increases. As a result, an increase in the sizeof the light source device 2 is caused.

In contrast, in the case of this embodiment, as explained above, thesecond reflection surface 63 b of the prism member 63 is disposed in theposition closer to the optical axis of the first lens 60 a. Therefore,the lens diameter of the first lens 60 a on which the excitation light Bis made incident decreases. It is possible to achieve a reduction in thesize of the light source device 2.

Based on such a configuration, the condensing optical system 60 in thisembodiment can condense the excitation light B emitted from the lightsource unit 20 and make the excitation light B incident on thewavelength conversion wheel 31 of the wavelength conversion unit 30. Theconfiguration of the wavelength conversion unit 30 is explained below.

In the case of this embodiment, the diffusion plate 65 is disposedbetween the condensing optical system 60 and the wavelength conversionunit 30 on an optical path of the excitation light B. The diffusionplate 65 diffuses the excitation light B and uniformizes a lightintensity distribution of the excitation light B on the wavelengthconversion wheel 31. As the diffusion plate 65, it is possible to use apublicly-known diffusion plate, for example, ground glass, a holographicdiffuser, a diffusion plate obtained by applying blasting to the surfaceof a transparent substrate, or a diffusion plate obtained by dispersinga scattering material such as beads on the inside of the transparentsubstrate to scatter light with the scattering material.

The wavelength conversion unit 30 emits fluorescent light YL aswavelength-converted light obtained by wavelength-converting theexcitation light B. The fluorescent light YL emitted from the wavelengthconversion unit 30 is made incident on the pickup optical system 61.

The pickup optical system 61 picks up wavelength-converted light emittedfrom the wavelength conversion wheel 31 and converts thewavelength-converted light into parallel light.

The pickup optical system 61 in this embodiment includes a plurality oflenses. The pickup optical system 61 in this embodiment is configured bythree convex lenses including a third lens 61 a, a fourth lens 61 b, anda fifth lens 61 c. The number of lenses configuring the pickup opticalsystem 61 is not particularly limited.

The third lens 61 a is disposed to be opposed to the wavelengthconversion unit 30. That is, the third lens 61 a is a lens locatedclosest to the light incident side in the pickup optical system 61.

The fourth lens 61 b is disposed on the opposite side of the lightsource unit 20 in the third lens 61 a, that is, a light emission side ofthe third lens 61 a.

The fifth lens 61 c is disposed on the opposite side of the light sourceunit 20 in the fourth lens 61 b, that is, the light emission side of thefourth lens 61 b.

In the pickup optical system 61 in this embodiment, the diameter of thethird lens 61 a located on the wavelength conversion wheel 31 side issmaller than the diameter of the fourth lens 61 b located closer to thelight emission side than the third lens 61 a. The diameter of the fourthlens 61 b is smaller than the diameter of the fifth lens 61 c locatedcloser to the light emission side than the fourth lens 61 b. That is,the lenses 61 a, 61 b, and 61 c configuring the pickup optical system 61have a larger outer diameter in the radial direction orthogonal to theoptical axis of the pickup optical system 61 as the lenses 61 a, 61 b,and 61 c are further away from the wavelength conversion unit 30. Theoptical axis of the pickup optical system 61 coincides with the opticalaxis AX3 of the condensing optical system 60.

Wavelength Conversion Unit

Subsequently, the configuration of the wavelength conversion unit 30 isexplained. FIG. 5 is a perspective view showing the configuration of thewavelength conversion unit 30. FIG. 6A is a diagram showing theconfiguration on a light incident surface side of the wavelengthconversion wheel 31. FIG. 6B is a diagram showing the configuration on alight emission surface side of the wavelength conversion wheel 31.

As shown in FIG. 5 , the wavelength conversion unit 30 includes thewavelength conversion wheel 31 and a wheel housing 32.

As shown in FIGS. 6A and 6B, the wavelength conversion wheel 31 includesa wheel substrate 311, a wavelength conversion element 312, and arotation driving section 313. The rotation driving section 313 isconfigured by, for example, a motor. Electric power is supplied to therotation driving section 313 via a flexible cable 316. The rotationdriving section 313 includes a rotation supporting section 313 a capableof rotating centering on a center axis O. The rotation supportingsection 313 a supports the wheel substrate 311 to be capable of rotatingcentering on the center axis O.

The wheel substrate 311 is configured from an annular metal plateexcellent in heat dissipation such as aluminum or copper.

The wavelength conversion element 312 is provided along the outercircumference of the wheel substrate 311. The wavelength conversionelement 312 is formed in a ring shape around the center axis O and hasan annular shape projecting in a brim shape from the outer circumferenceof the wheel substrate 311 toward the radial direction outer side. Theradial direction outer side means a direction that is orthogonal to thecenter axis O and away from the center axis O.

As shown in FIG. 5 , the wavelength conversion element 312 makes theexcitation light B emitted from the light emitting element 21 of thelight source unit 20 incident from a rear surface 312 a and emits, froma front surface 312 b, yellow fluorescent light YL obtained bywavelength-converting the excitation light B. That is, the wavelengthconversion element 312 is a light transmissive wavelength conversionelement that makes the excitation light B incident from the firstsurface 312 a and emits the wavelength-converted light YL from thesecond surface 312 b.

As the wavelength conversion element 312, YAG:Ce obtained by addingcerium ions, for example, Ce3+ to, for example, a garnet crystal (YAG)of Y₃Al₅O₁₂. A not-shown appropriate scattering element may be includedin the wavelength conversion element 312.

The wavelength conversion wheel 31 in this embodiment is a so-calledtransmissive phosphor wheel. Specifically, the wavelength conversionelement 312 transmits a part of the excitation light B made incidentfrom the rear surface 312 a and emits the part of the excitation light Bfrom the front surface 312 b together with the fluorescent light YL.Accordingly, the wavelength conversion element 312 emits the whiteillumination light WL obtained by combining blue component light BB,which is a part of the excitation light B, and the fluorescent light YL.

As shown in FIG. 6B, the wheel substrate 311 in this embodiment includesa plurality of fins 314 provided on the rear surface 312 a side of thewavelength conversion element 312 on which the excitation light B ismade incident. The plurality of fins 314 are provided on a rear surface311 b of the wheel substrate 311 . The plurality of fins 314 aredisposed around the center axis O to radially extend.

As shown in FIG. 6A, the wheel substrate 311 in this embodiment includesa plurality of fins 315 provided on the front surface 312 b side of thewavelength conversion element 312 that emits the excitation light B. Theplurality of fins 315 are provided on a front surface 311 a of the wheelsubstrate 311. The fins 315 are radially provided around the center axisO. In the case of this embodiment, temperature easily rises on the lightincident side of the wheel substrate 311 compared with the lightemission side. Therefore, a size of the fins 314 on the light incidentside is set larger than a size of the fins 315 on the light emissionside. A size relation between the fins 314 and 315 is not limited tothis. The fins 314 and 315 may have the same size or the fins 315 maybelarger than the fins 314.

With the wavelength conversion wheel 31 in this embodiment, it ispossible to generate an air current around the wavelength conversionelement 312 at a rotation time with the fins 314 and 315 provided onboth the surfaces of the wheel substrate 311 and cool the wavelengthconversion element 312. Consequently, it is possible to generate brightfluorescent light YL by improving wavelength conversion efficiency ofthe wavelength conversion element 312.

The wheel housing 32 houses the wavelength conversion wheel 31 as shownin FIG. 3 . The wheel housing 32 includes a first housing 321, a secondhousing 322, and a wheel sealing member 323 disposed between the firsthousing 321 and the second housing 322. The first housing 321 and thesecond housing 322 are fixed to each other in a sealed state via thewheel sealing member 323. The first housing 321 and the second housing322 are configured by a metal member excellent in heat dissipation suchas aluminum or stainless steel.

The first housing 321 is a plate-like member and includes a plurality ofheat radiation fins 120 provided on a surface 321 a and a couplingsection 121 extending to the second housing 322 side and coupled to thesecond housing 322. The first housing 321 is fixed to the second housing322 via the screw members 24. Screw holes 321H for inserting the screwmembers 24 are provided at four corners of the first housing 321. Acutout 121 a is provided at the outer edge on the right side +X whenviewed from a position on the +Y side. The cutout 121 a has asubstantially chevron shape.

The second housing 322 holds the wavelength conversion wheel 31. Thewavelength conversion wheel 31 is, for example, fixed to a bottom platesection 122 of the second housing 322 via not-shown screw members.

The second housing 322 includes the bottom plate section 122 that holdsthe wavelength conversion wheel 31, a side plate section 123 surroundingthe outer edge portions in three directions of the bottom plate section122, a flange section 124 provided on the opposite side of the bottomplate section 122 in the side plate section 123, a screw fasteningsection 125, and an attaching section 126. In the second housing 322, asshown in FIGS. 3 and 10 , a plurality of heat radiation fins 130 areprovided on the surface of the bottom plate section 122. Specifically,the wheel housing 32 in this embodiment includes the plurality of heatradiation fins 130 provided in a position not overlapping the opticalhousing 62 in the front-rear direction Y extending along the opticalaxis AX3 on the surface of the bottom plate section 122 of the secondhousing 322 facing the light source unit 20 side. Consequently, it ispossible to improve the heat dissipation of the wheel housing 32 whilepreventing interference of the heat radiation fins 130 and the opticalhousing 62.

As shown in FIG. 3 , in the bottom plate section 122, a cutout 122 a isprovided at the outer edge not surrounded by the side plate section 123.The cutout 122 a has a substantially chevron shape. The shape of thecutout 122 a of the bottom plate section 122 corresponds to the shape ofthe cutout 121 a of the first housing 321. That is, the cutouts 121 aand 122 a are formed to overlap each other when the wheel housing 32 isviewed in a plane view.

The flange section 124 is a part opposed to the first housing 321 andhas a substantially C-shaped plane shape. Overhanging sectionsoverhanging to the inner side and overlapping the external shape of thebottom plate section 122 in a plane view are respectively provided atboth distal ends of the flange section 124. The wheel sealing member 323is provided along the shape of the flange section 124.

The screw fastening section 125 is a part to which the screw members 24for fixing the first housing 321 to the second housing 322 are fastened.The screw fastening section 125 is provided integrally with a part ofthe flange section 124.

As shown in FIG. 3 , the attaching section 126 is a member for fixingthe wavelength conversion wheel 31 of the wavelength conversion unit 30to the optical housing 62 of the optical unit 40 with the screw members24.

As shown in FIG. 5 , the attaching section 126 includes a front sideattaching section 127, which is a first attaching section, and a rearside attaching section 128, which is a second attaching section.

The front side attaching section 127 includes a pair of front sideattachment plates 127 a provided in overhanging sections 124 a of theflange section 124. In the front side attachment plates 127 a, screwholes 127 b for inserting the screw members 24 are provided. The frontside attachment plates 127 a are provided to be orthogonal to theoverhanging sections 124 a and to be opposed to an attachment plate 83of an attaching section 80 of the optical housing 62. The front sideattachment plates 127 a are arranged in a row in the up-down directionZ. Specifically, the positions in the left-right direction X of thescrew holes 127 b of the front side attachment plates 127 a are equal.

The rear side attaching section 128 is provided on the rear side −Y,which is the opposite side of the first housing 321 in the bottom platesection 122 of the second housing 322. The rear side attaching section128 includes a pair of rear side attachment plates 128 a. In the rearside attachment plates 128 a, screw holes 128 b for inserting the screwmembers 24 are provided.

The rear side attachment plates 128 a are provided to be orthogonal tothe bottom plate section 122 and to be opposed to the attachment plate83 of the attaching section 80 of the optical housing 62. The rear sideattachment plates 128 are arranged in a row in the up-down direction Z.Specifically, positions in the left-right direction X of the screw holes128 b of the rear side attachment plates 128 a are equal.

Positions in the up-down direction Z of the front side attachment plates127 a and the rear side attachment plates 128 a arranged in thefront-rear direction Y are equal. Specifically, positions in the up-downdirection Z of the screw holes 127 b of the front side attachment plates127 a and the screw holes 128 b of the rear side attachment plates 128 aare equal.

As shown in FIG. 5 , the wheel housing 32 in this embodiment houses thewavelength conversion wheel 31 to expose a part of the wavelengthconversion wheel 31. The wheel housing 32 includes a wheel openingsection 33, which is a first opening section, for exposing a part of thewavelength conversion wheel 31.

The wheel opening section 33 is configured by at least one of the firsthousing 321 and the second housing 322. The wheel opening section 33 isconfigured by an end face of a portion where the cutout 121 a is formedin the first housing 321, an end face of the overhanging section 124 ain the second housing 322, an end face of the side plate section 123,and an end face of a portion where the cutout 122 a is formed in thebottom plate section 122. That is, in the case of this embodiment, thewheel opening section 33 is configured by the first housing 321 and thesecond housing 322. In the following explanation, end faces of the firsthousing 321 and the second housing 322 configuring the wheel openingsection 33 are referred to as “wheel opening end face 32 a”.

As shown in FIGS. 5 and 6A, the wavelength conversion element 312, whichis a part of the wavelength conversion wheel 31, is projected further tothe outer side than the wheel opening end face 32 a of the wheel housing32 via the wheel opening section 33.

Subsequently, a specific configuration of the optical housing 62 isexplained.

FIG. 7 is a perspective view showing a configuration on the rear side −Yof the optical housing 62.

FIGS. 8A and 8B are side views showing a main part configuration of theoptical housing 62. FIG. 8A is a side view of the optical housing 62viewed from the −X side. FIG. 8B is a side view of the optical housing62 viewed from the +X side.

FIG. 9 is a sectional view by a XI-XI line arrow view of FIG. 4 . FIG.10 is a perspective view showing a configuration in a cross section by asurface including a X-X line in FIG. 4 .

As shown in FIG. 7 , the optical housing 62 includes the attachingsection 80, a first member 85, and a second member 86. In thisembodiment, the attaching section 80, the first member 85, and thesecond member 86 are integrally formed. That is, the optical housing 62in this embodiment is configured by a single member. As shown in FIGS. 3and 4 , the first member 85 is a member that holds the condensingoptical system 60 and the second member 86 is a member that holds thepickup optical system 61.

As shown in FIG. 2 , the optical housing 62 includes a holding section64 held by the light source holding member 18 of the exterior housing 7via the screw members 9. As shown in FIG. 2 , the holding section 64includes screw fixing holes 64 a into which the screw members 9 fastenedto the screw fastening sections 18 a of the light source holding member18 are inserted and positioning holes 64 b into which the positioningsections 18 b of the light source holding member 18 are inserted.

As shown in FIGS. 8A and 8B, the first member 85 includes a light-sourcefixing section 70 and a first tubular section 90. The light source unit20 is fixed to the light-source fixing section 70 via the screw members24 (see FIG. 3 ).

As shown in FIG. 7 , the light-source fixing section 70 includes aholding surface 71, screw fastening sections 72, and a pair ofpositioning pins 73. The holding surface 71 holds the base member 23 ofthe light source unit 20 as shown in FIGS. 3 and 4 . The screw fasteningsections 72 are parts that are provided at four corners of the holdingsurface 71 having a rectangular shape and to which the screw members 24for fixing the light source unit 20 are fastened. The pair ofpositioning pins 73 is respectively provided in positions equivalent toboth the sides in the left-right direction X and the center in theup-down direction Z on the holding surface 71. As shown in FIGS. 3 and 4, the pair of positioning pins 73 is inserted into positioning holes 23a 1 formed in the fixing section 23 a of the base member 23 to positionthe base member 23 of the light source unit 20 with respect to thelight-source fixing section 70.

As shown in FIGS. 4 and 7 , the optical housing 62 in this embodimentincludes a prism supporting section 74, which is a first supportingsection that supports the prism member 63 of the condensing opticalsystem 60. The prism supporting section 74 is provided in thelight-source fixing section 70.

The prism supporting section 74 is formed to recess to the wavelengthconversion wheel 31 side from the holding surface 71 that holds thelight source unit 20. The prism supporting section 74 includes asupporting surface 74 a that supports the prism member 63. In the caseof this embodiment, a pair of supporting members 74 b that supports theprism member 63 is provided on the supporting surface 74 a of the prismsupporting section 74. The pair of supporting members 74 b isrespectively plate-like parts extending in the left-right direction Xand is provided on the supporting surface 74 a to be spaced in theup-down direction Z. Based on such a configuration, the prism supportingsection 74 can stably support the prism member 63 in a predeterminedposition on the supporting surface 74 a via the pair of supportingmembers 74 b.

As shown in FIG. 4 , the prism member 63 is disposed on the right side+X with respect to the optical axis AX3 of the condensing optical system60 when viewed from a position on the +Y side. The center of the lightsource unit 20 is located closer to the right side +X than the opticalaxis AX3. Accordingly, in the left-right direction X, the distance fromthe optical axis AX3 to the end face on the left side −X of thelight-source fixing section 70 of the optical housing 62 is shorter thanthe distance from the optical axis AX3 to the end face on the right side+X of the light-source fixing section 70 of the optical housing 62. Thatis, a projection amount of the optical housing 62 with respect to theoptical axis AX3 is larger on the left side −X than the right side +X.

The first tubular section 90 of the optical housing 62 includes a lenssupporting section 91, which is a second supporting section, and adiffusion-plate supporting section 92. The lens supporting section 91 isprovided on the inner surface side of the first tubular section 90 andis formed to recess to the wavelength conversion wheel 31 side from thesupporting surface 74 a of the prism supporting section 74.

The lens supporting section 91 includes a first step section 91 a thatsupports the first lens 60 a and a second step section 91 b thatsupports the second lens 60 b.

The first step section 91 a is configured by a step between a firstinner circumferential surface 90 a of the first tubular section 90 and asecond inner circumferential surface 90 b having a smaller innerdiameter than the first inner circumferential surface 90 a. The firstlens 60 a is supported in the lens supporting section 91 by the firststep section 91 a. The first lens 60 a may be fit in the first stepsection 91 a and fixed or may be fixed via a not-shown adhesive.

The second step section 91 b is a step between a third innercircumferential surface 90 c having a smaller inner diameter than thesecond inner circumferential surface 90 b and a fourth innercircumferential surface 90 d having a smaller inner diameter than thethird inner circumferential surface 90 c. The second lens 60 b issupported in the lens supporting section 91 by the second step section91 b. The second lens 60 b may be fit in the second step section 91 band fixed or may be fixed via a not-shown adhesive.

The diffusion-plate supporting section 92 is formed to recess to thewavelength conversion wheel 31 side from the bottom surface of the lenssupporting section 91. The diffusion-plate supporting section 92includes a supporting surface 92 a that supports the diffusion plate 65and an opening 92 b provided on the supporting surface 92 a. The opening92 b makes the excitation light B transmitted through the diffusionplate 65 incident on the wavelength conversion wheel 31.

The second member 86 of the optical housing 62 includes a connectingsection 99 and a second tubular section 95. As shown in FIG. 7 , theconnecting section 99 is provided to overhang to, from the outer edge ofthe distal end on the front side +Y of the second tubular section 95,the radial direction outer side to which the connecting section 99separates in a direction orthogonal to the optical axis AX3. Theconnecting section 99 is a member that connects the light source device2 to the uniform illumination optical system 5 shown in FIG. 1 .

Based on such a configuration, the light source device 2 in thisembodiment can efficiently make the illumination light WL incident onthe uniform illumination optical system 5 via the connecting section 99of the optical housing 62.

The second tubular section 95 mainly configured by a lens supportingsection 96 that supports the pickup optical system 61. The lenssupporting section 96 is provided on the inner surface of the secondtubular section 95. The lens supporting section 96 includes a third stepsection 96 a that supports the third lens 61 a, a fourth step section 96b that supports the fourth lens 61 b, and a fifth step section 96 c thatsupports the fifth lens 61 c.

The fifth step section 96 c is configured by a step between a fifthinner circumferential surface 95 a located closest to the front side +Yin the second tubular section 95 and a sixth inner circumferentialsurface 95 b located closer to the rear side −Y and having a smallerinner diameter than the fifth inner circumferential surface 95 a. Thefifth lens 61 c is supported in the lens supporting section 96 by thefifth step section 96 c. The fifth lens 61 c may be fit in the fifthstep section 96 c and fixed or may be fixed via a not-shown adhesive.

The fourth step section 96 b is configured by a step between a seventhinner circumferential surface 95 c located closer to the rear side −Yand having a smaller inner diameter than the sixth inner circumferentialsurface 95 b and an eighth inner circumferential surface 95 d locatedcloser to the rear side −Y and having a smaller inner diameter than theseventh inner circumferential surface 95 c. In the case of thisembodiment, a ninth inner circumferential surface 95 e connecting thesixth inner circumferential surface 95 b and the seventh innercircumferential surface 95 c is formed as a taper surface narrowed in aninner diameter toward the rear side −Y.

The fourth lens 61 b is supported in the lens supporting section 96 bythe fourth step section 96 b. The fourth lens 61 b may be fit in thefourth step section 96 b and fixed or may be fixed via a not-shownadhesive.

The third step section 96 a is configured by a step between a tenthinner circumferential surface 95 f located closer to the rear side −Yand having a smaller inner diameter than the eighth innercircumferential surface 95 d and an eleventh inner circumferentialsurface 95 g located closer to the rear side −Y and having a smallerinner diameter than the tenth inner circumferential surface 95 f. In thecase of this embodiment, the eighth inner circumferential surface 95 dis formed as a taper surface narrowed in an inner diameter stepwisetoward the rear side −Y.

The third lens 61 a is supported in the lens supporting section 96 bythe third step section 96 a. The third lens 61 a may be fit in the thirdstep section 96 a and fixed or may be fixed via a not-shown adhesive.

In this embodiment, the outer diameters of the lenses configuring thecondensing optical system 60 and the pickup optical system 61 decreaseas the lenses are closer to the wavelength conversion unit 30.

Consequently, in the optical housing 62 in this embodiment, adiameter-reduced section 69 is provided in a position corresponding tothe second lens 60 b of the condensing optical system 60 and the thirdlens 61 a of the pickup optical system 61. The diameter-reduced section69 is a part having a relatively smaller outer diameter than the otherportions in the optical housing 62.

In this embodiment, the wavelength conversion unit 30 is disposed in thediameter-reduced section 69 of the optical housing 62. Since thewavelength conversion unit 30 is attached to the optical housing 62 fromthe radial direction outer side, an increase in the dimension in theradial direction of the light source device 2 is prevented by disposingthe wavelength conversion unit 30 in the diameter-reduced section 69.

As shown in FIGS. 8A and 8B, the attaching section 80 is a part forattaching the wavelength conversion unit 30 to the optical housing 62.In this embodiment, by using the attaching section 80, the wavelengthconversion unit 30 including the wavelength conversion wheel 31 can beattached to the optical housing 62 from a plurality of directions withrespect to the optical axis AX3 of the condensing optical system 60.

The attaching section 80 includes a first attachment structure 81, asecond attachment structure 82, and an attachment plate 83 extendingalong a YZ plane. The attachment plate 83 connects the first tubularsection 90 and the second tubular section 95.

As shown in FIGS. 7 to 8B, the attachment plate 83 includes a firstattachment surface 83 a extending along the optical axis AX3 of thecondensing optical system 60 and facing the left side −X when viewedfrom a position on the +Y side, a second attachment surface 83 bextending along the optical axis AX3 of the condensing optical system 60and facing the right side +X opposite to the first attachment surface 83a when viewed from a position on the +Y side, and a through-hole 84.

The attachment plate 83 is located on the optical axis AX3 of thecondensing optical system 60.

In this embodiment, the attachment plate 83 being located on the opticalaxis AX3 of the condensing optical system 60 refers to a state in whichthe optical axis AX3 overlaps the first attachment surface 83 a or thesecond attachment surface 83 b or a state in which the optical axis AX3is located between the first attachment surface 83 a and the secondattachment surface 83 b.

In the case of this embodiment, in the attachment plate 83, the opticalaxis AX3 is located in the middle between the first attachment surface83 a and the second attachment surface 83 b. That is, in the attachmentplate 83 in this embodiment, the distance from the optical axis AX3 tothe first attachment surface 83 a and the distance from the optical axisAX3 to the second attachment surface 83 b are equal.

The through-hole 84 pierces through the attachment plate 83 in the platethickness direction. A plane shape of the through-hole 84 is arectangle. When the wavelength conversion unit 30 is attached to theattaching section 80, a part of the wavelength conversion wheel 31 isprojected from one side to the other side of the attachment plate 83through the through-hole 84.

The first attachment structure 81 enables the wavelength conversion unit30 to be attached to the first attachment surface 83 a. As shown in FIG.3 , in the light source device 2 in this embodiment, when viewed from aposition on the +Y side, the wavelength conversion unit 30 is attachedto the left side −X of the optical housing 62 via the first attachmentstructure 81. In the case of this embodiment, the wavelength conversionunit 30 is disposed between the heat radiating section 51 and theoptical unit 40.

As shown in FIG. 8A, the first attachment structure 81 is provided onthe first attachment surface 83 a. The first attachment structure 81includes a plurality of screw fastening sections 81 a and a pair ofpedestals 81 b projecting from the first attachment surface 83 a. In thecase of this embodiment, four screw fastening sections 81 a areprovided. As shown in FIG. 3 , the screw members 24 for attaching thewavelength conversion unit 30 are respectively fastened to the screwfastening sections 81 a. The pair of pedestals 81 b is disposed to beseparated in the front-rear direction Y. As shown in FIG. 9 , thepedestals 81 b are seats having a trapezoidal plane shape when viewedfrom a direction extending along the optical axis AX3 and function asseats for setting the wavelength conversion unit 30. The pedestals 81 bhave an external shape corresponding to the wheel opening end face 32 aof the wheel housing 32.

In the case of this embodiment, the width in the front-rear direction Yof the pedestal 81 b on the rear side −Y is larger than the width in thefront-rear direction Y of the pedestal 81 b on the front side +Y. Thisis because of a difference due to the width of contact with thewavelength conversion unit 30. Depending on the shape on the wavelengthconversion unit 30 side, the widths of the pedestals 81 b may be set thesame or the width on the front side +Y may be set larger than the widthon the rear side −Y.

The optical housing 62 in this embodiment includes a left side openingsection 87, which is a second opening section, provided on the firstattachment surface 83 a side of the attaching section 80. The left sideopening section 87 is an opening defined by a boundary between a spacesandwiched by the pair of pedestals 81 b and the outside of the space.

As shown in FIGS. 3 and 5 , when the wavelength conversion unit 30 isattached to the optical housing 62, the front side attachment plates 127a of the front side attaching section 127 and the rear side attachmentplates 128 a of the rear side attaching section 128 and the screwfastening sections 81 a of the first attachment structure 81 are fixedby the screw members 24. As shown in FIG. 8A, in the wheel housing 32,the wheel opening end face 32 a of the wheel housing 32 configuring thewheel opening section 33 collides with the pedestals 81 b and theattachment plate 83 of the first attachment structure 81 such that thewheel opening section 33 planarly surrounds the left side openingsection 87.

In the wavelength conversion unit 30, the wavelength conversion element312, which is a part of the wavelength conversion wheel 31, is locatedon an optical path between the condensing optical system 60 and thepickup optical system 61 in a state in which the wavelength conversionunit 30 is attached to the attaching section 80 of the optical housing62 of the optical unit 40.

That is, in this embodiment, in the optical unit 40 and the wavelengthconversion unit 30, the wavelength conversion element 312, which is apart of the wavelength conversion wheel 31 exposed via the wheel openingsection 33 of the wheel housing 32, is disposed on the optical pathbetween the condensing optical system 60 and the pickup optical system61 via the left side opening section 87 of the optical housing 62.

In the case of this embodiment, as shown in FIGS. 5 and 6A, thewavelength conversion element 312, which is a part of the wavelengthconversion wheel 31, projects further to the outer side than the wheelopening end face 32 a of the wheel housing 32 via the wheel openingsection 33. Accordingly, when the wavelength conversion unit 30 isattached to the optical housing 62, the wavelength conversion element312 projecting from the wheel opening end face 32 a is likely tointerfere with the attachment plate 83.

In contrast, in the attaching section 80 in this embodiment, as shown inFIGS. 5 and 10 , the through-hole 84 is provided in a positioncorresponding to the wavelength conversion element 312 projecting fromthe wheel opening end face 32 a to locate the wavelength conversionelement 312 projecting from the wheel opening end face 32 a on theopposite side of the attachment plate 83 via the through-hole 84. Inthis way, the wavelength conversion element 312 is disposed on theoptical axis AX3 of the condensing optical system 60. Therefore, it ispossible to efficiently make the excitation light B incident on thewavelength conversion element 312 via the condensing optical system 60.

In the case of this embodiment, since the optical axis of the pickupoptical system 61 coincides with the optical axis AX3 of the condensingoptical system 60, the illumination light WL emitted from the wavelengthconversion element 312 can be efficiently taken into the pickup opticalsystem 61. Accordingly, it is possible to improve light use efficiencyof the illumination light WL.

In this embodiment, as shown in FIG. 3 , a first sealing member 55 isdisposed between the wavelength conversion unit 30 and the opticalhousing 62. The wavelength conversion unit 30 is fixed to the firstattachment structure 81 of the optical housing 62 by the screw members24.

As shown in FIG. 9 , the first sealing member 55 is pressed between thewheel opening end face 32 a of the wheel housing 32 and the pedestal 81b and the first attachment surface 83 a of the first attachmentstructure 81. A gap between the left side opening section 87 of theoptical housing 62 and the wheel opening section 33 of the wheel housing32 is satisfactorily closed by the first sealing member 55.

In this way, the optical unit 40 and the wavelength conversion unit 30are fixed in a state in which the left side opening section 87 of theoptical housing 62 and the wheel opening section 33 of the wheel housing32 are sealed.

The second attachment structure 82 enables the wavelength conversionunit 30 to be attachable to the second attachment surface 83 b. As shownin FIG. 8B, the second attachment structure 82 includes a plurality ofscrew fastening sections 82 a and a pair of pedestals 82 b provided onthe second attachment surface 83 b. In the case of this embodiment, fourscrew fastening sections 82 a are provided.

The second attachment structure 82 has the same configuration as theconfiguration of the first attachment structure 81. Accordingly, in theoptical housing 62, the wavelength conversion unit 30 can be attached tothe second attachment structure 82 by changing an attaching direction ofthe wavelength conversion unit 30.

In the case of this embodiment, as explained above, the wavelengthconversion unit 30 is attached to the optical housing 62 using the firstattachment structure 81. Therefore, the second attachment structure 82is not used to attach the wavelength conversion unit 30.

The optical housing 62 in this embodiment includes a right side openingsection 88, which is a third opening section, provided on the secondattachment surface 83 b side of the attaching section 80. The right sideopening section 88 is an opening defined by a boundary between a spacesandwiched by the pair of pedestals 82 b and the outside of the space.The right side opening section 88 is opposed to the left side openingsection 87 across the attachment plate 83 of the attaching section 80.

The condensing optical system 60 and the pickup optical system 61 onwhich the excitation light B is made incident generate heat. In thelight source device 2 in this embodiment, as shown in FIG. 2 , the lidbody 53 thermally connected to the second heat conducting section 52 bof the second cooling section 50B is attached to the second attachmentstructure 82. Consequently, cooling performance of the condensingoptical system 60 and the pickup optical system 61 is improved byradiating heat received from the optical housing 62.

As shown in FIG. 3 , the lid body 53 includes a lid main body section 53a and an attaching section 53 b. The lid main body section 53 a of thelid body 53 has an external shape corresponding to the pedestals 82 b ofthe second attachment structure 82 and the pedestals 81 b having thesame shape as the pedestals 82 b.

When the lid body 53 is attached to the optical housing 62, theattaching section 53 b of the lid body 53 and the screw fasteningsections 82 a of the second attachment structure 82 are fixed by thescrew members 24. At this time, as shown in FIG. 8B, the lid main bodysection 53 a of the lid body 53 collides with the pedestals 82 b and theattachment plate 83 of the second attachment structure 82 to close theright side opening section 88.

In this embodiment, as shown in FIG. 3 , a second sealing member 56 isdisposed between the lid body 53 and the optical housing 62. The lidbody 53 is fixed to the second attachment structure 82 of the opticalhousing 62 by the screw members 24. Consequently, a gap between theright side opening section 88 of the optical housing 62 and the lid mainbody section 53 a of the lid body 53 is satisfactorily closed by thesecond sealing member 56. Accordingly, as shown in FIG. 8B, the lid body53 is fixed to the optical housing 62 in a state in which the lid body53 covers the right side opening section 88 of the optical housing 62 ina sealed state.

As explained above, in the light source device 2 in this embodiment, thelight source unit 20 and the optical unit 40 are fixed in the sealedstate. In the optical unit 40 and the wavelength conversion unit 30, apart of the wavelength conversion wheel 31 exposed via the wheel openingsection 33 of the wheel housing 32 is disposed on the optical pathbetween the condensing optical system 60 and the pickup optical system61 via the left side opening section 87 of the optical housing 62. Theleft side opening section 87 of the optical housing 62 and the wheelopening section 33 of the wheel housing 32 are fixed in the sealedstate.

With the light source device 2 in this embodiment, it is possible toprovide a light source device having a sealed structure in which thewavelength conversion wheel 31 is disposed on the optical path betweenthe condensing optical system 60 and the pickup optical system 61 andthe three units, that is, the light source unit 20, the wavelengthconversion unit 30, and the optical unit 40 are fixed in the sealedstate. Consequently, since intrusion of dust into the inside of thelight source device 2 is prevented, it is possible to prevent occurrenceof deficiencies such as deterioration and heat generation of componentscaused by dust adhering to the lenses and the wavelength conversionwheel 31. Since the light source device 2 is configured by the threeunits, it is possible to provide the light source device 2 excellent inassemblability.

In the case of this embodiment, in the optical housing 62, thewavelength conversion unit 30 is disposed in the diameter-reducedsection 69 having the smaller outer diameter than the other portions.Accordingly, a projection amount of the wavelength conversion unit 30from the optical housing 62 is reduced. It is possible to prevent anincrease in the size of the light source device 2.

In the case of this embodiment, the optical housing 62 of the opticalunit 40 and the base member 23 of the light source unit 20 are fixed inthe sealed state.

With this configuration, in the light source unit 20, not the mountingsubstrate 22 on which the light emitting element 21 is mounted but theoptical housing 62 is fixed to the base member 23. Therefore, the sealedstate can be easily realized.

In the case of this embodiment, the optical path of the excitation lightB2 emitted from the second light emitting element 212 can be changed bythe prism member 63 to reduce the light beam width of the excitationlight B made incident on the condensing optical system 60. Accordingly,it is possible to generate the bright fluorescent light YL by increasinga light amount of the excitation light B while preventing an increase inthe size of the condensing optical system 60 on which the excitationlight B is made incident.

In the case of this embodiment, in the first cooling section 50A thatcools the optical unit 40, the heat of the base member 23 is conductedto the first heat radiating section 51 a via the first heat conductingsection 52 a. With this configuration, flexibility of disposition of thefirst heat radiating section 51 a is improved by changing routing of thefirst heat conducting section 52 a. Accordingly, it is possible toprovide the light source device 2 in which a layout change is easy.

In the case of this embodiment, the wheel housing 32 of the wavelengthconversion unit 30 is configured by the first housing 321 and the secondhousing 322. The wheel opening section 33 of the wheel housing 32 isconfigured by the first housing 321 and the second housing 322.

With this configuration, the wheel housing 32 including the wheelopening section 33 can be configured by the two housings. Therefore, itis possible to improve assemblability of the wavelength conversion unit30.

In the case of this embodiment, in the optical housing 62, the firstmember 85 that holds the condensing optical system 60 and the secondmember 86 that holds the pickup optical system 61 are integrally formed.Therefore, the number of components can be reduced. If the opticalhousing 62 is configured by a plurality of components, adjustment isnecessary because of tolerance of the components. However, in thisembodiment, since the optical housing 62 is configured by one component,the adjustment is unnecessary. It is possible to improve assemblability.

In the case of this embodiment, the optical unit 40 further includes thelid body 53 that covers, in the sealed state, the right side openingsection 88 opposed to the left side opening section 87 of the opticalhousing 62.

With this configuration, the wavelength conversion unit 30 can beattached to the right side opening section 88 of the optical housing 62as well. Accordingly, the wavelength conversion unit 30 can be attachedto the optical housing 62 from both the sides in the left-rightdirection X. Therefore, flexibility of the layout of the wavelengthconversion unit 30 is improved.

It is possible to maintain the sealed state in the light source device 2by closing, with the lid body 53, an opening section not used to attachthe wavelength conversion unit 30.

In the case of this embodiment, as shown in FIG. 2 , in the secondcooling section 50B, heat received by the lid body 53 from thewavelength conversion unit 30, the condensing optical system 60, thepickup optical system 61, or the light source unit 20 via the opticalhousing 62 can be conducted to the second heat radiating section 51 bvia the second heat conducting section 52 b. Accordingly, it is possibleto improve cooling performance while simplifying a device configurationof the light source device 2.

In the light source device 2 in this embodiment, to enable thewavelength conversion wheel 31 to be disposed from two directions withrespect to the optical axis AX3 of the condensing optical system 60, theoptical unit 40 includes the attaching section 80 to which thewavelength conversion unit 30 is attached.

With the light source device 2 in this embodiment, the wavelengthconversion wheel 31 can be disposed from two directions with respect tothe optical housing 62 of the optical unit 40. Therefore, flexibility ofthe layout of the light source device 2 can be improved. Accordingly,the light source device 2 in which a layout change corresponding tospecifications can be easily performed is provided.

In the case of this embodiment, the attaching section 80 includes theattachment plate 83 including the first attachment surface 83 aextending along the optical axis AX3 of the condensing optical system 60and the second attachment surface 83 b opposite to the first attachmentsurface 83 a. The wavelength conversion unit 30 is attached to one ofthe first attachment surface 83 a and the second attachment surface 83b.

With this configuration, it is possible to realize, with the attachmentplate 83, a configuration in which the wavelength conversion unit 30 issymmetrically disposed with respect to the optical axis AX3.

In the case of this embodiment, the attachment plate 83 is located onthe optical axis AX3 of the condensing optical system 60.

With this configuration, the distance from the wavelength conversionunit 30 attached to the first attachment surface 83 a to the opticalaxis AX3 and the distance from the wavelength conversion unit 30attached to the second attachment surface 83 b to the optical axis AX3are the same. Accordingly, it is easy to align the wavelength conversionunit 30 and the optical axis AX3 and assemblability is improved.

In the case of this embodiment, the attaching unit 80 includes the firstattachment structure 81 that enables the wavelength conversion unit 30to be attached to the first attachment surface 83 a and the secondattachment structure 82 that enables the wavelength conversion unit 30to be attached to the second attachment surface 83 b and having the sameconfiguration as the configuration of the first attachment structure 81.

With this configuration, it is possible to attach the wavelengthconversion units 30 having the same structure to both the surfaces ofthe attachment plate 83. Accordingly, it is possible to provide a lightsource device in which a layout change can be easily performed whilereducing cost by using the wavelength conversion units 30 in commonirrespective of attaching directions.

In the case of this embodiment, the wavelength conversion wheel 31 makesthe excitation light B incident from the rear surface 312 a and emitsthe yellow fluorescent light YL obtained by wavelength-converting theexcitation light B from the front surface 312 b. Further, in the statein which the wavelength conversion unit 30 is attached to the attachingsection 80 of the optical unit 40, a part of the wavelength conversionwheel 31 is located on the optical path between the condensing opticalsystem 60 and the pickup optical system 61.

With this configuration, in the transmissive wavelength conversion wheel31, it is possible to improve flexibility of the layout of the lightsource device 2.

In the case of this embodiment, the cooling unit 50 includes the heatradiating section 51 disposed in parallel to the optical unit 40 and theheat conducting section 52 that conducts heat received by the basemember 23 of the light source unit 20 to the heat radiating section 51.

With this configuration, it is possible to efficiently cool the lightemitting element 21 of the light source unit 20.

In the case of this embodiment, the wavelength conversion unit 30 isdisposed between the heat radiating section 51 and the optical unit 40.Therefore, when viewed from a position on the +Y side, a space can besecured on the right side +X, which is the opposite side of thewavelength conversion unit 30 with respect to the optical unit 40.Accordingly, for example, it is possible to reduce the size of a deviceconfiguration of the projector 1 by disposing projector components inthe space on the right side +X of the optical unit 40.

The light source device 2 in this embodiment includes the prism member63 that changes the optical path of the excitation light B2 emitted fromthe second light emitting element 212 to be closer to the excitationlight B1 emitted from the first light emitting element 211 and makes theexcitation light B2 incident on the first lens 60 a of the condensingoptical system 60. The optical housing 62 includes the prism supportingsection 74 that supports the prism member 63 and the lens supportingsection 91 that supports the condensing optical system 60. The holdingsurface 71 of the optical housing 62 and the base member 23 are fixed.

The light source device 2 in this embodiment is configured by the threeunits, that is, the light source unit 20, the wavelength conversion unit30, and the optical unit 40. The prism member 63 that changes theoptical path of the excitation light B2 emitted from the second lightemitting element 212 and makes the excitation light B2 incident on thecondensing optical system 60 is disposed in the optical housing 62together with the condensing optical system 60. Therefore, it ispossible to generate the bright illumination light WL while reducing thesize of a device configuration of the light source device 2.

In the case of this embodiment, the second reflection surface 63 b ofthe prism member 63 is located between the first lens 60 a and the firstmounting substrate 221 in the front-rear direction Y extending along theoptical axis AX3 of the condensing optical system 60. Therefore, it ispossible to prevent an increase in the size of the light source device 2in the left-right direction X, which is an arranging direction of thefirst mounting substrate 221 and the second mounting substrate 222.

In the case of this embodiment, the base member 23 includes the recess23 b. The first mounting substrate 221 and the second mounting substrate222 are set in the recess 23 b.

With this configuration, when the holding surface 71 of the opticalhousing 62 and the base member 23 of the light source unit 20 are fixed,a housing space for the light emitting element 21 can be secured in therecess 23 b.

In the case of this embodiment, in the left-right direction X crossingthe optical axis AX3 of the condensing optical system 60, when viewedfrom a position on the +Y side, the wavelength conversion unit 30 isdisposed on the left side −X in the left-right direction X with respectto the optical housing 62 and the prism member 63 is disposed on theright side +X in the left-right direction X with respect to the opticalaxis AX3 in the optical housing 62.

With this configuration, a space can be secured on the right side +X,which is the opposite side of the wavelength conversion unit 30 withrespect to the optical unit 40. Accordingly, it is possible to reducethe size of the device configuration of the projector 1 by, for example,disposing the projector components in the space on the right side +X ofthe optical unit 40.

In the case of this embodiment, the wheel housing 32 includes theplurality of heat radiation fins 130 in the position not overlapping theoptical housing 62 in the front-rear direction Y extending along theoptical axis AX3 on the surface of the second housing 322 facing thelight source unit 20 side.

With this configuration, it is possible to improve heat dissipation ofthe wheel housing 32 while effectively using a space not overlapping theoptical housing 62 on the surface of the second housing 322.

The projector 1 in this embodiment includes the light source device 2,the image forming device 3 that forms light output from the light sourcedevice 2 into image light, and the projection optical device 6 thatprojects the image light output from the image forming device 3.

Since the projector 1 in this embodiment includes the light sourcedevice 2 that prevents intrusion of dust, it is possible to provide aprojector having high reliability by preventing an operation failure ofthe light source device 2 due to dust. Since a dust collecting filterfor preventing intrusion of dust into the light source device 2 can beomitted, the device configuration of the projector 1 can be simplified.

According to this embodiment, the projector 1 includes the light sourcedevice 2 that generates the bright illumination light WL while beingreduced in the size of the device configuration. Therefore, it ispossible to provide a projector that is small in size and displays abright image.

According to this embodiment, since the projector 1 includes the lightsource device 2 with improved flexibility of the layout, it is possibleto provide a projector having high flexibility of the layout of aninternal configuration. Accordingly, a projector having a high addedvalue for facilitating a layout change corresponding to specificationsis provided.

Second Embodiment

Subsequently, a light source device in a second embodiment is explained.

The light source device in this embodiment is different from the lightsource device in the first embodiment in an attaching direction of thewavelength conversion unit 30 to the optical unit 40. Components andmembers common to the first embodiment are denoted by the same referencenumerals and signs and explanation is omitted about details of thecomponents and the members.

FIG. 11 is a perspective view showing a schematic configuration of alight source device 2A in this embodiment.

As shown in FIG. 11 , in the light source device 2A in this embodiment,when viewed from a position on the +Y side, the wavelength conversionunit 30 is attached to the right side +X of the optical unit 40.

In this embodiment, when the wavelength conversion unit 30 is attachedto the right side +X of the optical housing 62, that is, when thewavelength conversion unit 30 is attached to the opposite side of thecooling unit 50 with respect to the condensing optical system 60, theattaching section 126 of the wavelength conversion unit 30 and the screwfastening sections 82 a of the second attachment structure 82 are fixedby the screw members 24. Since the second attachment structure 82 hasthe same configuration as the configuration of the first attachmentstructure 81, it is possible to attach the wavelength conversion unit 30to the second attachment structure 82 by rotating the wavelengthconversion unit 30 180° around the optical axis AX3.

In this embodiment, as shown in FIG. 3 , the wavelength conversion unit30 and the prism member 63 are respectively disposed on the right side+X, which is one side in the left-right direction X crossing the opticalaxis AX3 of the first lens 60 a of the condensing optical system 60,with respect to the optical housing 62. That is, the wavelengthconversion unit 30 and the prism member 63 are located on the same rightside +X with respect to the optical axis AX3. A part of the wavelengthconversion unit 30 overlaps the prism member 63 in the front-reardirection Y extending along the optical axis AX3.

In the case of this embodiment, the wavelength conversion unit 30 isattached to the optical housing 62 using the second attachment structure82. Therefore, the first attachment structure 81 is not used to attachthe wavelength conversion unit 30.

In the light source device 2A in this embodiment, when viewed from aposition on the +Y side, the lid body 53 thermally connected to thesecond heat conducting section 52 b of the second cooling section 50B isattached to the left side −X of the optical unit 40 using the firstattachment structure 81.

In this embodiment, when the lid body 53 is attached to the left side −Xof the optical housing 62, the attaching section 53 b of the lid body 53and the screw fastening sections 81 a of the first attachment structure81 are fixed by the screw members 24.

In this way, in the light source device 2A in this embodiment, whenviewed from a position on the +Y side, the wavelength conversion unit 30is disposed on the right side +X in the left-right direction X in whichthe external shape of the optical housing 62 further projects withrespect to the optical axis AX3.

With the light source device 2A in this embodiment, when the wavelengthconversion unit 30 is attached to the optical housing 62, the width ofthe wavelength conversion unit 30 projecting in the left-right directionX from the end face of the light-source fixing section 70 of the opticalhousing 62 can be reduced to be smaller than the width in theconfiguration of the light source device 2 in the first embodiment.Therefore, with the light source device 2A in this embodiment, it ispossible to achieve a reduction in the size of a device configuration ofthe light source device 2A by further reducing the size in theleft-right direction X.

In this embodiment, the wavelength conversion unit 30 is disposed on theright side +X, which is the opposite side of the heat radiating section51 with respect to the optical unit 40. In this case, compared with aconfiguration in which the wavelength conversion unit 30 is disposed onthe same side as the heat radiating section 51 with respect to theoptical unit 40 as in the first embodiment, a space is formed betweenthe light source unit 20 and the heat radiating section 51. Therefore,it is desirable to effectively use this excess space.

FIG. 12 is a plan view showing the configuration of a light sourcedevice in a modification in which the excess space is effectively used.In FIG. 12 , illustration of a heat conducting section connected to thelid body 53 is omitted in order to clearly show the figure.

As shown in FIG. 12 , a first heat radiating section 151 a and a secondheat radiating section 151 b in a heat radiating section 151respectively include extending portions 150 a and 150 b extending to aportion overlapping the excess space SP. With the heat radiating section151, it is possible to improve heat radiation performance by enlargingthe area of the heat radiating section 151 and prevent an increase inthe size of the device configuration of the light source device by usingthe excess space SP.

Third Embodiment

Subsequently, a light source device in a third embodiment is explained.

The light source device in this embodiment is different from the lightsource devices in the first embodiment and the second embodiment in theconfiguration of an optical unit. Components and members common to theembodiments explained above are denoted by the same reference numeralsand signs and explanation is omitted about details of the components andthe members.

FIG. 13 is a perspective view showing a schematic configuration of alight source device 2B in this embodiment.

As shown in FIG. 13 , the light source device 2B in this embodimentincludes the light source unit 20, an optical unit 140, the wavelengthconversion unit 30, and the cooling unit 50.

FIG. 14 is an exploded perspective view showing the configuration of thelight source device 2B.

As shown in FIG. 14 , the optical unit 140 in the light source device 2Bin this embodiment includes an optical housing 162 different in a shapefrom the embodiments explained above. The optical housing 162 includesan attaching section 180, the first member 85, and the second member 86.

The optical housing 162 in this embodiment is different from the opticalhousing 62 in the first and second embodiments in that the attachingsection 180 is rotated 90° around the optical axis AX3 of the condensingoptical system 60 shown in FIG. 3 with respect to the first member 85and the second member 86. The configuration other than the layout of theattaching section 180 in the optical housing 162 is generally common tothe optical housing 62 in the first and second embodiments. Therefore,explanation is omitted about details of the configuration.

In the case of this embodiment, the wavelength conversion unit 30 can beattached from a plurality of directions, specifically, two directions inthe up-down direction Z with respect to the optical axis AX3 by usingthe attaching section 180 of the optical housing 162. In thisembodiment, the wavelength conversion unit 30 is disposed, with respectto the optical unit 140, in the up-down direction Z crossing theleft-right direction X in which the optical unit 140 and the heatradiating section 51 are adjacent to each other.

Specifically, in the light source device 2B in this embodiment, whenviewed from a position on the +Y side, the wavelength conversion unit 30is attached to the lower side −Z of the optical unit 140 via the firstsealing member 55 by the screw members 24 and the lid body 53 isattached to the upper side +Z of the optical unit 140 via the secondsealing member 56 by the screw members 24.

FIGS. 15A and 15B are side views showing a main part configuration ofthe optical housing 162. FIG. 15A is a bottom view of the opticalhousing 162 viewed from the −Z side. FIG. 15B is a top view of theoptical housing 162 viewed from the +Z side.

As shown in FIGS. 15A and 15B, in the optical housing 162 in thisembodiment, the attaching section 180 includes the first attachmentstructure 81, the second attachment structure 82, and an attachmentplate 183 extending along an XY plane. The attachment plate 183 in thisembodiment includes a first attachment surface 183 a extending along theoptical axis AX3 of the condensing optical system 60 and facing thelower side −Z, a second attachment surface 183 b extending along theoptical axis AX3 of the condensing optical system 60 and facing theupper side +Z opposite to the first attachment surface 183 a, and thethrough-hole 84. The attachment plate 183 is located on the optical axisAX3 of the condensing optical system 60.

The optical housing 162 enables, with the first attachment structure 81,the wavelength conversion unit 30 to be attached to the lower side −Z.

The optical housing 162 in this embodiment includes a lower side openingsection 187, which is a second opening section, provided on the firstattachment surface 183 a side of the attaching section 180. The lowerside opening section 187 is an opening defined by a boundary between aspace sandwiched by the pair of pedestals 81 b and the outside of thespace.

As shown in FIG. 14 , when the wavelength conversion unit 30 is attachedto the lower side −Z of the optical housing 162, the attaching section126 of the wavelength conversion unit 30 and the screw fasteningsections 81 a of the first attachment structure 81 shown in FIG. 15A arefixed by the screw members 24. At this time, as shown in FIG. 15A, inthe wheel housing 32, the wheel opening end face 32 a of the wheelhousing 32 configuring the wheel opening section 33 collides with thepedestals 81 b and the attachment plate 183 of the first attachmentstructure 81 such that the wheel opening section 33 planarly surroundsthe lower side opening section 187.

In this embodiment as well, the wavelength conversion element 312, whichis a part of the wavelength conversion wheel 31 exposed via the wheelopening section 33 of the wheel housing 32, is disposed on the opticalpath between the condensing optical system 60 and the pickup opticalsystem 61 via the lower side opening section 187 of the optical housing162 in a state in which the wavelength conversion unit 30 is attached tothe attaching section 180 of the optical housing 162 of the optical unit40.

As shown in FIG. 14 , in the optical unit 40 and the wavelengthconversion unit 30, the lower side opening section 187 of the opticalhousing 162 and the wheel opening section 33 of the wheel housing 32 arefixed in a sealed state by the first sealing member 55.

In the optical housing 162, the wavelength conversion unit 30 can beattached to the upper side +Z as well by the second attachment structure82. However, as explained above, the wavelength conversion unit 30 isattached to the lower side −Z of the optical housing 162 using the firstattachment structure 81. Accordingly, in this embodiment, the secondattachment structure 82 is not used to attach the wavelength conversionunit 30.

The optical housing 162 in this embodiment includes an upper sideopening section 188, which is a third opening section, provided on thesecond attachment surface 183 b side of the attaching section 180. Theupper side opening section 188 is an opening defined by a boundarybetween a space sandwiched by the pair of pedestals 82 b and the outsideof the space. The upper side opening section 188 is opposed to the lowerside opening section 187 across the attachment plate 183 of theattaching section 180.

As shown in FIG. 14 , when the lid body 53 is attached to the opticalhousing 162, the attaching section 53 b of the lid body 53 and the screwfastening sections 82 a of the second attachment structure 82 are fixedby the screw members 24. At this time, as shown in FIG. 15B, in the lidbody 53, the lid main body section 53 a collides with the pedestals 82 band the attachment plate 83 of the second attachment structure 82 toclose the upper side opening section 188.

In the optical unit 40 and the lid body 53, the upper side openingsection 188 of the optical housing 162 and the lid body 53 are fixed ina sealed state by the second sealing member 56.

In this way, with the light source device 2B in this embodiment, it ispossible to provide a light source device having a sealed structure thatenables the wavelength conversion unit 30 to be attached to the opticalunit 140 from the two directions in the up-down direction Z.

The embodiment of the present disclosure is explained above as anexample. However, the present disclosure is not always limited to theembodiment. Various changes can be applied without departing from thegist of the present disclosure.

For example, in the first embodiment, as an example, the first member 85and the second member 86 are integrally formed in the optical housing62. However, the first member 85 and the second member 86 may be formedby separate bodies. For example, the optical housing 62 may beconfigured by coupling, with the attachment plate 83, the first member85 and the second member 86 formed by the separate bodies. With thisconfiguration, since the first member 85 and the second member 86 areconfigured by separate members, it is easy to incorporate the condensingoptical system 60 and the pickup optical system 61 in the first member85 and the second member 86.

In the embodiment, as an example, the wheel opening section 33 of thewheel housing 32 is configured by the first housing 321 and the secondhousing 322. However, the wheel opening section 33 may be configured byonly one of the first housing 321 and the second housing 322.

In the embodiment, as an example, the attachment section 80 of theoptical housing 62 is located on the optical axis AX3 of the condensingoptical system 60. However, the attachment plate 83 may be disposed todeviate in any one direction in the left-right direction X with respectto the optical axis AX3.

In each of the optical housings 62 and 162 in the embodiments explainedabove, the two opening sections are provided to enable the wavelengthconversion unit 30 to be attached from the two directions. The openingsection to which the wavelength conversion unit 30 is not attached iscovered by the lid body 53. However, only one opening section to whichthe wavelength conversion unit 30 is attached may be provided.

In the light source device 2 in the first embodiment, when viewed from aposition on the +Y side, the wavelength conversion unit 30 is disposedon the left side −X in the left-right direction X in which a projectionamount of the external shape of the optical housing 62 is small withrespect to the optical axis AX3. Therefore, when the wavelengthconversion unit 30 is attached to the optical housing 62, overlap in theleft-right direction X of the second housing 322 of the wheel housing 32of the wavelength conversion unit 30 and the optical housing 62decreases.

That is, compared with when the wavelength conversion unit 30 isattached to the right side +X of the optical housing 62, the surfacearea of the second housing 322 exposed from the optical housing 62increases. Therefore, if the wavelength conversion unit is not used incommon in the embodiments, about the wavelength conversion unit 30attached to the left side −X of the optical housing 62 as in the firstembodiment, the heat dissipation of the wheel housing 32 may be furtherimproved by increasing the size of the heat radiation fins 130 providedon the surface of the second housing 322 exposed from the opticalhousing 62.

A light source device according to an aspect of the present disclosuremay have the following configuration.

The light source device according to the aspect of the presentdisclosure includes: a light source unit including a light emittingelement; a wavelength conversion unit including: a wavelength conversionwheel configured to make excitation light emitted from the lightemitting element incident from a first surface and emitwavelength-converted light obtained by wavelength-converting theexcitation light from a second surface opposite to the first surface;and a wheel housing including a first opening section for exposing apart of the wavelength conversion wheel and configured to house thewavelength conversion wheel; and an optical unit including: a condensingoptical system including a first lens for condensing the excitationlight on the wavelength conversion wheel; a pickup optical systemconfigured to pick up the wavelength-converted light; and an opticalhousing including a second opening section for receiving a part of thewavelength conversion wheel and configured to hold the condensingoptical system and the pickup optical system to locate a part of thewavelength conversion wheel on an optical path between the condensingoptical system and the pickup optical system. The light source unit andthe optical unit are fixed in a sealed state. In the optical unit andthe wavelength conversion unit, a part of the wavelength conversionwheel exposed via the first opening section of the wheel housing isdisposed on the optical path between the condensing optical system andthe pickup optical system via the second opening section of the opticalhousing. The second opening section of the optical housing and the firstopening section of the wheel housing are fixed in a sealed state.

In the light source device according to the aspect of the presentdisclosure, the condensing optical system and the pickup optical systemmay respectively include pluralities of lenses, in the condensingoptical system, a diameter of a second lens located closer to thewavelength conversion wheel side than the first lens may be smaller thana diameter of the first lens, in the pickup optical system, a diameterof a third lens located on the wavelength conversion wheel side may besmaller than a diameter of a fourth lens located closer to a lightemission side than the third lens, the optical housing may include adiameter-reduced section having a smaller outer diameter than otherportions in a position corresponding to the second lens of thecondensing optical system and the third lens of the pickup opticalsystem, and the wavelength conversion unit may be disposed in thediameter-reduced section.

In the light source device according to the aspect of the presentdisclosure, the light source unit may further include: amountingsubstrate on which a light emitting element is mounted; and a basemember on which the mounting substrate is placed, the base memberreceiving heat of the light emitting element, and the optical housing ofthe optical unit and the base member of the light source unit may befixed in a sealed state.

In the light source device according to the aspect of the presentdisclosure, the light source unit may include a plurality of the lightemitting elements and a plurality of the mounting substrates, theplurality of light emitting elements may include a first light emittingelement and a second light emitting element, the plurality of mountingsubstrates may include a first mounting substrate on which the firstlight emitting element is mounted and a second mounting substrate onwhich the second light emitting element is mounted, the condensingoptical system may further include an optical-path changing memberconfigured to change an optical path of the excitation light emittedfrom the second light emitting element, the excitation light emittedfrom the first light emitting element may be directly made incident onthe first lens of the condensing optical system, and the excitationlight emitted from the second light emitting element may be madeincident on the first lens of the condensing optical system through theoptical-path changing member.

In the light source device according to the aspect of the presentdisclosure, the light source device may further include a first coolingsection configured to cool the optical unit, the first cooling sectionmay include a first heat radiating section and a first heat conductingsection configured to thermally connect the first heat radiating sectionand the base member, and heat of the base member may be conducted to thefirst heat radiating section via the first heat conducting section.

In the light source device according to the aspect of the presentdisclosure, the wheel housing of the wavelength conversion unit mayinclude a first housing and a second housing fixed to each other in asealed state, and the first opening section of the wheel housing may beconfigured by at least one of the first housing and the second housing.

In the light source device according to the aspect of the presentdisclosure, the optical housing may include a first member configured tohold the condensing optical system and a second member configured tohold the pickup optical system, and the first member and the secondmember may be formed by a single member.

In the light source device according to the aspect of the presentdisclosure, the optical housing may include a first member configured tohold the condensing optical system and a second member configured tohold the pickup optical system, and the first member and the secondmember may be formed by separate bodies.

In the light source device according to the aspect of the presentdisclosure, the optical housing may include a third opening sectionseparately from the second opening section of the optical housing, andthe optical unit may further include a lid body configured to cover thethird opening section in a sealed state.

In the light source device according to the aspect of the presentdisclosure, the light source device may further include a second coolingsection configured to cool the optical unit, the second cooling sectionmay include a second heat radiating section and a second heat conductingsection configured to thermally connect the second heat radiatingsection and the lid body, and heat received by the lid body may beconducted to the second heat radiating section via the second heatconducting section.

A projector according to an aspect of the present disclosure may havethe following configuration.

The projector according to the aspect of the present disclosure include:the light source device according to the aspect explained above; animage forming device configured to form light output from the lightsource device into image light; and a projection optical deviceconfigured to project the image light output from the image formingdevice.

What is claimed is:
 1. A light source device comprising: a light sourceunit including a light emitting element; a wavelength conversion unitincluding: a wavelength conversion wheel configured to make excitationlight emitted from the light emitting element incident from a firstsurface and emit wavelength-converted light obtained bywavelength-converting the excitation light from a second surfaceopposite to the first surface; and a wheel housing including a firstopening section for exposing a part of the wavelength conversion wheeland configured to house the wavelength conversion wheel; and an opticalunit including: a condensing optical system including a first lens forcondensing the excitation light on the wavelength conversion wheel; apickup optical system configured to pick up the wavelength-convertedlight; and an optical housing including a second opening section forreceiving a part of the wavelength conversion wheel and configured tohold the condensing optical system and the pickup optical system tolocate a part of the wavelength conversion wheel on an optical pathbetween the condensing optical system and the pickup optical system,wherein the light source unit and the optical unit are fixed in a sealedstate, in the optical unit and the wavelength conversion unit, apart ofthe wavelength conversion wheel exposed via the first opening section ofthe wheel housing is disposed on the optical path between the condensingoptical system and the pickup optical system via the second openingsection of the optical housing, and the second opening section of theoptical housing and the first opening section of the wheel housing arefixed in a sealed state.
 2. The light source device according to claim1, wherein the condensing optical system and the pickup optical systemrespectively include pluralities of lenses, in the condensing opticalsystem, a diameter of a second lens located closer to the wavelengthconversion wheel side than the first lens is smaller than a diameter ofthe first lens, in the pickup optical system, a diameter of a third lenslocated on the wavelength conversion wheel side is smaller than adiameter of a fourth lens located closer to a light emission side thanthe third lens, the optical housing includes a diameter-reduced sectionhaving a smaller outer diameter than other portions in a positioncorresponding to the second lens of the condensing optical system andthe third lens of the pickup optical system, and the wavelengthconversion unit is disposed in the diameter-reduced section.
 3. Thelight source device according to claim 1, wherein the light source unitfurther includes: a mounting substrate on which a light emitting elementis mounted; and a base member on which the mounting substrate is placed,the base member receiving heat of the light emitting element, and theoptical housing of the optical unit and the base member of the lightsource unit are fixed in a sealed state.
 4. The light source deviceaccording to claim 3, wherein the light source unit includes a pluralityof the light emitting elements and a plurality of the mountingsubstrates, the plurality of light emitting elements include a firstlight emitting element and a second light emitting element, theplurality of mounting substrates include a first mounting substrate onwhich the first light emitting element is mounted and a second mountingsubstrate on which the second light emitting element is mounted, thecondensing optical system further includes an optical-path changingmember configured to change an optical path of the excitation lightemitted from the second light emitting element, the excitation lightemitted from the first light emitting element is directly made incidenton the first lens of the condensing optical system, and the excitationlight emitted from the second light emitting element is made incident onthe first lens of the condensing optical system through the optical-pathchanging member.
 5. The light source device according to claim 3,further comprising a first cooling section configured to cool theoptical unit, wherein the first cooling section includes a first heatradiating section and a first heat conducting section configured tothermally connect the first heat radiating section and the base member,and heat of the base member is conducted to the first heat radiatingsection via the first heat conducting section.
 6. The light sourcedevice according to claim 1, wherein the wheel housing of the wavelengthconversion unit includes a first housing and a second housing fixed toeach other in a sealed state, and the first opening section of the wheelhousing is configured by at least one of the first housing and thesecond housing.
 7. The light source device according to claim 1, whereinthe optical housing includes a first member configured to hold thecondensing optical system and a second member configured to hold thepickup optical system, and the first member and the second member areformed by a single member.
 8. The light source device according to claim1, wherein the optical housing includes a first member configured tohold the condensing optical system and a second member configured tohold the pickup optical system, and the first member and the secondmember are formed by separate bodies.
 9. The light source deviceaccording to claim 7, wherein the optical housing includes a thirdopening section separately from the second opening section of theoptical housing, and the optical unit further comprises a lid bodyconfigured to cover the third opening section in a sealed state.
 10. Thelight source device according to claim 9, further comprising a secondcooling section configured to cool the optical unit, wherein the secondcooling section includes a second heat radiating section and a secondheat conducting section configured to thermally connect the second heatradiating section and the lid body, and heat received by the lid body isconducted to the second heat radiating section via the second heatconducting section.
 11. A projector comprising: the light source deviceaccording to claim 1; an image forming device configured to form lightoutput from the light source device into image light; and a projectionoptical device configured to project the image light output from theimage forming device.